if you put a thrid party label inside, they intentionally make the print look bad. but if you glue their RFID sticker inside to that thirdparty label, it prints perfectly!
I bought this useless junk from niimbot. Now i had to use it so my money is not wasted.

But i strongly advice you not to buy any junk from these little creeps so they learn not to trick people with their single digit IQ. It is a label printer , not a rocketscience after all. just find another brand.